Professional consensus on screening mammography after age 70 is lacking because comorbidities can complicate the decision of whether to screen elderly women for breast cancer. When practice guidelines are unclear, providers' values and patients' perceptions and beliefs may influence this decision making. OBJECTIVES/AIMS: 1) To identify the impact of comorbid conditions on mammography utilization, stage at diagnosis, treatment, and differences in survival among female Medicare beneficiaries over 65 years of age without a prior history of breast cancer. 2) Using clinical vignettes featuring women of different ages with different comorbidities, to identify physician and patient characteristics that influence physicians' decisions about mammography screening when practice guidelines are unclear. 3) To determine whether the effects of comorbid conditions, age, and race/ethnicity on mammographic screening among elderly women are related to their willingness to accept mammography and their perceptions of the associated benefits and barriers. METHODS: We propose to study the linked database of Medicare claims (information on mammography utilization and treatment of breast cancer) and the California Cancer Registry (information on stage at diagnosis, tumor size and other characteristics) to identify comorbid conditions among women aged 67 years or older who were newly diagnosed with invasive breast cancer in 1993 through 2002. A self- administered questionnaire and case vignettes will be mailed to a random sample of 600 physicians in metropolitan Sacramento. We will conduct 15-20 minute interviews of 150 female patients attending primary care clinics at UCDMC, within thirty days of an encounter. RATIONALE: Breast cancer in the elderly is becoming more prevalent as the US population ages, yet we have little evidence as to the effectiveness of mammographic screening in women over 70-74 years of age, and practice guidelines are unclear. This research program will generate improved estimates of current practices and the health consequences of those practices, while evaluating physician and patient factors that influence decision-making among elderly women. By integrating quantitative and qualitative methods, we hope to develop a framework that clinicians can use to assess the harms and benefits, and policy-makers can use to assess the cost-effectiveness, of breast cancer screening for elderly women with comorbidities.